This a list of songs I find essential to the Pet Shop Boys Canon that don't show up on Discography or Popart:

1.  Two Divided By Zero**

2.  Tonight Is Forever**

3.  Was That What It Was*

4.  In The Night**

5.  Paninaro**

6.  One More Chance*

7.  It Couldn't Happen Here

8.  Kings Cross**

9.  Do I Have To?*

10.  I Want A Dog

11.  I'm Not Scared

12.  This Must Be The Place I Waited Years To Leave**

13.  The End Of The World*

14.  How Can You Expect To Be Taken Seriously**

15.  Be She's Not Your Girlfriend

16.  Up Against It

17.  The Survivors

18.  Closer To Heaven

19.  Footsteps

20.  Betrayed

21.  Delusions Of Grandeur

22.  The View From Your Balcony

23.  The Boy Who Couldn't Keep His Clothes On

24.  My Night**

25.  It's Just My Little Tribute To Caligula, Darling!*

26.  London

27.  Email*

28.  Samurai In Autumn*

29.  The Ressurectionist

30.  Fugitive*

31.  Minimal**

32.  I'm With Stupid**

33.  Integral

34.  The Sodom And Gomorrah Show

35.  Numb

36.  Casanova In Hell*

37.  Only Love** (Super hard to find demo)

Two Stars is get the song for sure if you like the main hits, one star is you will likely like it, and no stars are still essential, just not quite as good to me as the others.